The dilemma for all critics is the program / repertoire.

Just recall the first impression when you first heard a song or a piece of music.
Try to comment on a recital of which the program is in your repertoire deposit account.

Not very happy a thing to do, I' d confess.

It's almost like judging at a school exam.
People born in the later half of 20th century basically believe – if not worship -the sanity of composers' notations and indications; therefore, authenticity readily became one of the hottest issues in musicology and performance practice.

Not until recently did critical writings on classical music domain in Taiwan flee from the version comparing fashion. Comparative version studies are interesting in history of performance and perhaps history of recordings, but it's not as interesting or proper comparing two pianists' performance and interpretation just because they play the same piece.

Why?

Because live performances are IRREVERSIBLE and IRREPEATABLE.
Not even musicians playing the same repertoire “repeatedly” in a season can copy their previous performances.

----to be continued